Method and apparatus for wrapping products



March 12, 1963 R'. BENNER 3,080,691

METHOD AND APPARATUS FOR WRAPPING PRODUCTS Filed Dec. 14. 1960 3 Sheets-Sheet 1 Mare 12 1963 R. BENNER 3,080,691

METHOD AND APPARATUS FOR WRAPPING PRODUCTS Filed D80. 14, 1950 3 Sheets-Sheet 2 INVENTOR,

R. BENNER March 12, 1963 METHOD AND APPARATUS FOR WRAPPING PRODUCTS Filed Dec. 14. 1960 3 Sheets-Sheet 3 3,086,691 METI-IQD AND APPARATUS FOR WRAPPING PRODUCTS Robert Banner, Nampa, Idaho, assignor to Armour and Company, Chicago, Ill., a corporation of Delaware Filed Dec. 14, 1960, Ser. No. 75,863 4 Claims. (Cl. 53-228) This invention relates to processes and apparatus for producing tightly wrapped packages.

In the wrapping of products it is very important to States PatentO maintain a tight wrap around the product. First, a loosely Wrapped package is unattractive from a marketing standpoint; second, a tightly wrapped package allows less film to be used per package, and so there is an economic advantage to a tightly wrapped package.

It is therefore an object of this invention to provide a process which produces a tightly wrapped package. It is a further object of this invention to provide a simply constructed device which performs this process. It is also an object' of this invention to provide a wrapping film tightening process and device which provides a tightly wrapped package and at the same time does not cause the package to be overly tight so as to damage the product. Other objects and purposes of this invention will become obvious as the specification proceeds.

An embodiment of the apparatus is illustrated in the accompanying drawings. FIG. 1 is a partially sectioned sideview of the invention and its related parts; FIG. 2 is an enlarged partially sectioned view of a wrapping chamber utilizing the present invention, before the wrapping material is tucked around the product; FIG. 3 is an enlarged partially sectioned view of a Wrapping chamber utilizing the present invention, after the wrapping material has been tucked around the product; FIG. 4 is an enlarged partially sectioned view of a wrapping chamber utilizing the present invention during the heat sealing step; FIG. 5 is a view taken along lines 55 of FIG. 1; FIG. 6 is a top view of a pocket wheel utilizing the present invention; FIG. 7 is a bottom view of one wrapping chamber or pocket utilizing the present invention; and FIG. 8 is a perspective view of a product that has been wrapped by a machine utilizing the present invention.

Generally, the device comprises a product wrapping chamber 10 having resilient members 11 disposed across the wrapping chamber 10.

The wrapping chamber or pocket 10 comprises four walls 13, 14, 15 and 16 and two opposite open ends, one end being the product inlet end 12. Resilient members 11 are disposed across inlet end 12 of wrapping chamber 19. Terminal portions 18 of resilient members 11 are secured to spring clips 19 which are fastened to support plate 20. Support plate 20 is secured to wall 14 of wrapping chamber 10 by screws 21. Terminal portions 22 of resilient members 11 may likewise be fastened to wall 16 by means of clips 19, plate 21 and screws 21. It is preferred that resilient members 11 be of fiat spring material.

It is preferred that resilient cross supports 23 be utilized. These supports 23 are positioned around resilient members 11, extending across and transverse to members 11 on the inlet end 12 of wrapping chamber 10 and passing around surfaces 17 of walls 13 and 15. Resilient cross supports 23 are secured to walls 13 and 15 by means of screws 24. These cross supports 23 have a dampening effect on the vibration of resilient members 11 when a wrapped package is released. Cross supports 23 are preferably of sheet rubber material.

Referring to FIGS. 1 and 5, there is an illustration of a wrapping machine which is known to the art and which may utilize the present invention. Belt conveyor 25 carries the product 26 to be wrapped. In this example,

Patented Mar. 12, 1963 frankfurters are illustrated as the product 26. The product 26, utilizing cardboard sleeve 27, is shown more '33. Passing over product 26 is wrapping material 34,

which is maintained on roll 35. Wrapping material 34 is moved over product 26 by means of vacuum wheels 36. Vacuum wheels 36 are provided with holes 37 which communicate with a vacuum source, not shown. Wrapping material 34, by covering holes 37 of vacuum wheels 36, is moved over product 26 upon rotational movement of vacuum wheels 36. Since vacuum wheels are wellknown in the art, a further description is believed to be unnecessary. Wheels 36 are provided with cutting blocks 3711. at which place wrapping material 34 is cut by knives 38 on cutting wheel 39. Sleeve 40 has approximately the same internal dimensions as wrapping chamber 10 and is positoned above product 26 and wrapping material 34. Fingers 41 are positioned between sleeve 40 and wrapping chamber 10 and perform the folding operation of wrapping material 34 around product 26. Pocket wheel 42, shown in FIG. 6, utilizes six pockets or wrapping chambers 10a to 101 in which the wrapping operation is performed. Pocket wheel 42 is adapted to rotate about shaft 43, whereby pocket 10a is indexed to the position formerly occupied by pocket 10b, pocket 10b is indexed to the position formerly occupied by pocket 10c. etc. the position occupied by pocket 10b, the heat sealing operation is perform Referring to FIG. 4, there is an illustration of the heat sealing station. Heating plate 47 is connected to shaft 48 which in turn is hingedly fastened to arm 49 by pin 59. Shaft 48 is guided by bearings 51 and 52. Electrical cable 53 passes into heating plate 47 so as to provide the electrical heat for the sealing operation.

Now that the apparatus has been described the operation will be described. Referring to FIG. 1, the product 26 is carried along conveyor 25 and is pushed across table 29 by pusher 28, and is positioned on platform 30 of elevator 31. While product 26 is being positioned, vacuum wheels 36 are rotating, in the direction shown, causing the positioning of wrapping material 34 over product 26. After the required amount of wrapping material 34 has been positioned over product 26, vacuum wheels 36 stop and knife 38 cuts wrapping film 34. Then platform 3%) and rod 33 rise, lifting wrapping material 34 and product 26 through sleeve 40 and into wrapping chamber 10. Sleeve 40 causes wrapping material 34 to be formed loosely around product 26.

Referring to FIG. 3, after product 26 has been carried into the'pocket l0, elevator 31 drops down but rod 33 remains in contact with product 26. It can be seen in FIG. 2 that resilient members 11 provide a positive force against the wrapping film 34 and the product as soon as film 34 and product 26 enter pocket 10, whereby the wrapping film 34 is maintained tightly against product 26. After platform 30 has dropped down, fingers 41 fold film 34 around product 26. Fingers 41 retract after performing the folding operation. Rod 33 holds product 26 tightly against resilient members 11 during the folding operation. After folding, the pocket wheel 42 indexes one station, and the heat sealing operation is performed. Product 26 is maintained tightly between heating element 47 and'between resilient members 11 during heat sealing. The pocket wheel continues to index until wrapped product 2-6 is discharged. At this time, cross supports 23 perform one of their functions in that they prevent excessive stretching and vibration of resilient members 11 and this prevents undue wear of resilient members 11.

From the explanation it should be clear that resilient w pp n material 91? fi m a d P o whereby film 34 is maintained snugly against product 26 at all times.

It is particularly important that resilient members-11 conform substantially to the leading surfaces 53 of product 26, leading surfaces including leading end 54 and sides 55.

It is to be understood that this invention is not to be limited to the specific embodiment depicted in the drawings and specification; rather, it is intended that all equivalents obvious to those skilled in the art be included within the scope ofthis invention.

Now that the invention has been described, I claim:

1. In an improved product wrapping machine of the type utilizing a series of wrapping pockets, the improvement comprising resilient members fastened to opposite walls of said pocket and stretched across the product inlet end of said pockets whereby pressure is exerted against the end and sides of said product in order to produce a tightly wrapped product.

2. A wrapping material tightening device comprising a product wrapping chamber having a product inlet end, resilient members positioned across said inlet end, and resilient cross supports extending across and transverse to said resilient members on said inlet end, and extending a product, comprising the steps of positioning wrapping material between a wrapping chamber and a product,

forcing said material and said product against a resilient resistance which conforms substantially to the leading surfaces of said product so as to apply pressure to the end and sides of said product in order to produce a tightly wrapped product, and then completing the wrap ping of said product.

References Cited in the file of this patent UNITED STATES PATENTS 2,208,776 Sandberg July 23, 1940 

1. IN AN IMPROVED PRODUCT WRAPPING MACHINE OF THE TYPE UTILIZING A SERIES OF WRAPPING POCKETS, THE IMPROVEMENT COMPRISING RESILIENT MEMBERS FASTENED TO OPPOSITE WALLS OF SAID POCKET AND STRETCHED ACROSS THE PRODUCT INLET END OF SAID POCKETS WHEREBY PRESSURE IS EXERTED AGAINST THE END AND SIDES OF SAID PRODUCT IN ORDER TO PRODUCE A TIGHTLY WRAPPED PRODUCT. 